/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    https://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.grails.cli.compiler;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.codehaus.groovy.ast.ASTNode;
import org.codehaus.groovy.ast.AnnotatedNode;
import org.codehaus.groovy.ast.AnnotationNode;
import org.codehaus.groovy.ast.ClassCodeVisitorSupport;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.ImportNode;
import org.codehaus.groovy.ast.ModuleNode;
import org.codehaus.groovy.control.SourceUnit;
import org.codehaus.groovy.transform.ASTTransformation;

/**
 * A base class for {@link ASTTransformation AST transformations} that are solely
 * interested in {@link AnnotatedNode AnnotatedNodes}.
 *
 * @author Andy Wilkinson
 * @since 1.1.0
 */
public abstract class AnnotatedNodeASTTransformation implements ASTTransformation {

    private final Set<String> interestingAnnotationNames;

    private final boolean removeAnnotations;

    private SourceUnit sourceUnit;

    protected AnnotatedNodeASTTransformation(Set<String> interestingAnnotationNames, boolean removeAnnotations) {
        this.interestingAnnotationNames = interestingAnnotationNames;
        this.removeAnnotations = removeAnnotations;
    }

    @Override
    public void visit(ASTNode[] nodes, SourceUnit source) {
        this.sourceUnit = source;
        List<AnnotationNode> annotationNodes = new ArrayList<>();
        ClassVisitor classVisitor = new ClassVisitor(source, annotationNodes);
        for (ASTNode node : nodes) {
            if (node instanceof ModuleNode) {
                ModuleNode module = (ModuleNode) node;
                visitAnnotatedNode(module.getPackage(), annotationNodes);
                for (ImportNode importNode : module.getImports()) {
                    visitAnnotatedNode(importNode, annotationNodes);
                }
                for (ImportNode importNode : module.getStarImports()) {
                    visitAnnotatedNode(importNode, annotationNodes);
                }
                module.getStaticImports()
                    .forEach((name, importNode) -> visitAnnotatedNode(importNode, annotationNodes));
                module.getStaticStarImports()
                    .forEach((name, importNode) -> visitAnnotatedNode(importNode, annotationNodes));
                for (ClassNode classNode : module.getClasses()) {
                    visitAnnotatedNode(classNode, annotationNodes);
                    classNode.visitContents(classVisitor);
                }
            }
        }
        processAnnotationNodes(annotationNodes);
    }

    protected SourceUnit getSourceUnit() {
        return this.sourceUnit;
    }

    protected abstract void processAnnotationNodes(List<AnnotationNode> annotationNodes);

    private void visitAnnotatedNode(AnnotatedNode annotatedNode, List<AnnotationNode> annotatedNodes) {
        if (annotatedNode != null) {
            Iterator<AnnotationNode> annotationNodes = annotatedNode.getAnnotations().iterator();
            while (annotationNodes.hasNext()) {
                AnnotationNode annotationNode = annotationNodes.next();
                if (this.interestingAnnotationNames.contains(annotationNode.getClassNode().getName())) {
                    annotatedNodes.add(annotationNode);
                    if (this.removeAnnotations) {
                        annotationNodes.remove();
                    }
                }
            }
        }
    }

    private class ClassVisitor extends ClassCodeVisitorSupport {

        private final SourceUnit source;

        private final List<AnnotationNode> annotationNodes;

        ClassVisitor(SourceUnit source, List<AnnotationNode> annotationNodes) {
            this.source = source;
            this.annotationNodes = annotationNodes;
        }

        @Override
        protected SourceUnit getSourceUnit() {
            return this.source;
        }

        @Override
        public void visitAnnotations(AnnotatedNode node) {
            visitAnnotatedNode(node, this.annotationNodes);
        }

    }

}
